1. Field of Disclosure
The disclosure relates to a static random-access (SRAM) cell and, more specifically, to a five-transistor SRAM cell.
2. Related Art
A random-access-memory (RAM) cell is a semiconductor memory which stores information as a single bit value. A static random-access-memory (SRAM) cell is a type of RAM cell that stores a bit value using bistable latching circuitry which is formed from a pair of cross-coupled inverters. The bistable latching circuitry is comprised of four transistors, but additional transistors, known as access transistors, are required for the memory controller to access to the SRAM cell to read the content of the cell and to write data to the cell.
SRAM cells can be connected together to form an array. In a world of ever-shrinking modern electronics, SRAM arrays are advantageous in that a larger amount of SRAM can be provided in a smaller physical space compared to SRAM cells operating independently in isolation. An SRAM array is generally designed using a number of individual SRAM cells connected in a grid pattern, with an individual SRAM cell accessed as part of an addressable row and column system. A memory controller together with memory driver circuitry can read and/or write to the SRAM array in a random fashion, as any particular cell value can be accessed at any particular time given the address of the row and column associated with an individual SRAM cell.
Because of the ability of the SRAM cell to hold a bit value, changing the cell bit value can involve various processes intended to “overpower” the state of some of the latching circuitry transistors over others utilizing the access transistors. The additional power handling required to overpower the access transistors results in an undesirable increase in size. The additional access transistors and the increased access transistor sizes places limitations on further reductions of the physical size of an SRAM array.
The disclosure will now be described with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the reference number.